Widescreen time-compressed/time-expanded television signal transmitting/receiving system

Abstract

A compatible widescreen television signal transmission system includes a device for separating a widescreen television signal into a center panel signal component and left and right side panel signal components. The left and right panel signal components are preemphasized. A compatible widescreen television signal receiving system includes a device for time-division demultipling the widescreen television signal into the center panel signal component and the left and right side panel signal components. The left and right panel signal components are deemphasized.

What is claimed is: 
     
       1. A compatible widescreen television signal transmission system comprising: a signal having a center panel signal component and left and right side panel signal components;   means for separating said widescreen television signal into said center panel signal component and said left and right side panel signal components;   means for time-expanding said center panel signal component;   means for time-compressing said left and right side panel signal components;   means for preemphasizing said time-compressed left and right means for time-division multiplexing said time-expanded center panel signal component with said time-compressed and preemphasized side panel signal components;   means for encoding said multiplex signal in accordance with a standard television signal; and   means for transmitting said encoded signal.   
     
     
       2. The system of claim 1 further including means for nonlinearly compressing said time-compressed and preemphasized side panel signal components. 
     
     
       3. The system of claim 1, wherein said time-expanding means expands said center panel signal components by the factor of 4/3. 
     
     
       4. The system of claim 1, wherein said time-compressing means compresses said left and right side panel signal components by the factor of 1/4. 
     
     
       5. The system of claim 1, wherein said preemphasizing means comprises a recursive network. 
     
     
       6. The system of claim 1, wherein said preemphasizing means includes a summing means, a first delay means, a multiplying means and a second delay means, wherein the summing means operates to subtract a second signal from a first signal which is an input to said preemphasizing means and to output the resulting signal as said preemphasized signal, the first delay means operates to delay the output of said summing means by a specified period, the multiplying means operates to multiply said delayed output of said first delay means by a prescribed coefficient, and the second delay means operates to delay the output of said multiplying means by said specified period and to output that delayed signal as said second signal. 
     
     
       7. A compatible widescreen television signal having a center panel signal component and left and right side panel signal components, further comprising: means for separating said widescreen television signal into said center panel signal component and said left and right side panel signal components;   means for time-expanding said center panel signal component;   means for preemphasizing said left and right side panel signal components;   means for time-compressing said preemphasized left and right side panel signal components;   means for time-division multiplexing said time-expanded center panel signal component with said time-compressed and preemphasized side panel signal components;   means for encoding said multiplex signal in accordance with a standard television signal; and   means for transmitting said encoded signal.   
     
     
       8. A compatible widescreen television signal receiving system comprising: means for receiving an encoded widescreen television signal having a time-expanded center panel signal component and time-compressed and preemphasized left and right side panel signal components;   means for decoding said received television signal;   means for time-division demultiplying said decoded signal into said center panel signal component and said left and right side panel signal components;   means for time-compressing said center panel signal component;   means for deemphasizing said left and right side panel signal components;   means for time-expanding said deemphasized left and right panel signal components;   means for composing the widescreen television signal of said time-compressed center panel signal component and said time-expanded and deemphasized left and right side panel signal components.   
     
     
       9. The system of claim 8, further including means for supplying the composed widescreen television signal to a receiver. 
     
     
       10. The system of claim 8, further including means for nonlinearly expanding said time-division demultiplied left and right side panel signal components. 
     
     
       11. The system of claim 8, wherein said time-compressing means compresses said center panel signal component by the factor of 3/4. 
     
     
       12. The system of claim 8, wherein said time-expanding means expands said left and right side panel signal components by the factor of 4. 
     
     
       13. The system of claim 8, wherein said deemphasizing means comprises a nonrecursive network. 
     
     
       14. The system of claim 8, wherein said deemphasizing means includes a first delay means, a multiplying means, a second delay means and a summing means, wherein the first delay means operates to delay an input signal thereof by a specified period, the multiplying means operates to multiply said delayed output of said first delay means by a prescribed coefficient, the second delay means operates to delay the output of said multiplying means by said specified period, and the summing means operates to sum said delayed signal output from said second delay means and said input signal. 
     
     
       15. The system of claim 8, further including means for compensating for differences in the signal to noise ratio of said center panel signal component and said left and right side panel signal components. 
     
     
       16. The system of claim 15, wherein said compensating means includes a first delay circuit, an adder circuit, an amplifier circuit, a high pass filter circuit and a second delay circuit, wherein the first delay circuit, having a two horizontal scan period delay factor, receives said decoded signal the adder circuit combines by substraction said decoded signal from said two horizontal scan period delayed signal, the amplifier circuit attenuates said combined signal by a signal gain of 0.5 , the high pass filter receives said attenuated signal and extracts a noise signal in the high frequency region, the second delay circuit delays said noise signal for a prescribed period. 
     
     
       17. The system of claim 16, wherein said compensating means provides a high frequency noise signal to the widescreen television signal. 
     
     
       18. A compatible widescreen television signal receiving system comprising: means for receiving an encoded widescreen television signal having a time-expanded center panel signal component and time-compressed and preemphasized left and right side panel signal components;   means for decoding said received television signal;   means for time-division demultiplying said decoded signal into said center panel signal component and said left and right side panel signal components;   means for time-compressing said center panel signal component;   means for time-expanding said left and right side panel signal components;   means for composing the widescreen television signal of said time-compressed center panel signal component and said time-expanded and deemphasized left and right side panel signal components.